Grease gun



Nova, L 1927 1,647,941

No STORY, 3D

GREASE GUN Filed June 8. 1925 10 4 k 47 3 26 if 11 l l 1 1a 21 INVENTOR 7d JWGZJOR A? $073 5 ATTORNEYS WITNESSES ltl lli

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NELSON STORY, 3!), E BOZEMAN, MUNTANAQM canteen eon.

Application filed June a,

'lihis invention relates to lubricating devices and pertains to certain improvements in what are lrnown as grease guns for feedlubricant under pressure to the bearings or other parts to be lubricated.

I @ne' of the outstanding objects of the present invention is to provide a simple, in enpensive convenient device for economically feeding lubricant under pressure to the parts to he lubricated.

ihe invention furthermore comprehende ,tates the operation of supplying the in ant without undue waste or over-feedn the invention comprecating device which includes a ow body constantly filled with a supply or lubricant under a normal relatively low pr sure; which body is provided with a valved outlet nozzle closed against the es of the luhricant under said normal pressure with rueans for causing an increase in normal reassure whereby to eiiect the predetermined quantities of hibrieant. I With the above recited and other objects view, reference is'had to the following specification and accompanying drawings in which there is exhibited one example or embodiment oi the invention which is in no way intended as a limitation upon the scope or the appended claims as it is to be clearly understood that variations and modifica tions which. properly fall within the scope ot said claims may be resorted to when found enpedient.

in the guns 1 longitudinal sectional view ough a grease gun constructed in accordwit invention and illustratlng the it it.

, position of parts when the same are in normal inactive condition;

Fig. 2 is a fragmentary longitudinal see tionai view illustrating the manually con trolled means moved to a position for actu ating the gun; V

Fig. 3 is horizontal sectional view taken approximately on the line 3 --3 of Fig. 1;

Fig. 4 is a transverse sectlonal yiew taken approximately on the line or Fig. 1;

ltig. 5 is a horizontal sectional view taken approximately on the line 5- 5 of Fig.

Fig. 6 is a fragmentary side view IllHS" training the trigger structure.

Referring to the drawings by characters improved grease gun which greatly fa 1926. serial its. M43586,

of reference, the grease gun comprises substantially hollow cylindrical body 10 hav ing a reduced end 11 formed with an outlet bore 12 and constituting an outlet nozzle The opposite end is provided with a removable closure cap 131 through which extends a lubricant conduit pipe 14ileading from a series oiE lubricant supply. A plunger valve 15 is mounted in the inner end of the bore 120i the outer end or nozzle 11 the valve being provided with axial here 16 extending inwardly from its outer end and communicating with the radial port 1? intermediate its ends. The plunger valve is normally forced inwardly and tensioned against outward movement b a coiled ex pansion spring 18 interposed between the outer end of the plunger valve and a suit able abutment pin 19. The outer end of the "m nozzle carries and communicates with a nipple 20 within which a normally closed out wardly opening and inwardly closing check valve 21 is arranged. The nipple may furthen be provided with a bayonet slot or other similar coupling means 22 for attaching the nipple oi the gun to a suitable comple mentary receiving device mounted on the part to be lubricated. The lubricant is supplied to the interior of the body it} and maintained under a normal relatively low pressure slightly in excess of atmospheric pressure, while the tension. on the check valve 21 is slightly greater than said non mal internal. pressure for preventing escape of the lubricant.

In order to provide convenient means for facilitating the discharge of a predetermined quantity of the lubricant from the gun body, a rock lever 23 is fulcrurned within the body 10 by means of trunnions 24: disposed in a bearing recess 25, one end 26 of the rock lever engaging-the headed. inner end 2'? of the plunger valve 15 and serving when the rock lever is in normal position to limit the inward movement of the plunger valve so that the radial port 17 is disposed in com munication with the interior of the body 100 The lever is swung downwardly to its normal position'by means of a spring 2% and the means for inching the lever upwardly to cause its end 26 to move the plunger valve outwardly in the bore 12 against the action of the springs 18 and 28, consists of a plunger or piston 29 freely mounted for movement 11 in a plunger cylin or 30 depending from'the body 10 and having an open inner end (30mm gg earner municating with the same. The outer ends is closed by a cylinder head 31 and suitable means, such as a projection 31 formed on the cylinder head, limits the outward movement of the plunger or piston 29 and normally spaces the same from the outer closed end of the cylinder. The rock lever 23 has its free 32 projecting into the inner open end of the cylinder 30 and engaging w th the piston or plunger 29, so that upon. inward movement of the piston or plunger, the rock lever is swung upwardly to perform its function.

Compressed air or other similar fluid force is employed for moving the piston or plunger 29 inwardly and the means for 1n troducing the compressed air preferably consists of a conduit pipe 33 connected by a flexible hose 34 to a source of supply, the pipe 33 leading upwardly alongside the forward portion of the cylinder 30 to a valve casing 35 which preferably forms an 1nt-egral depending part or boss of the body 10. A rotary valve core 36 is mounted in the valve casin 35, and is provided with a passage 37 which upon turning movement of the valve core is adapter to respectively establish and cut oil communication between the pipe 33 and a pipe section 38, which leads from the valve casing to the cylinder 30 adjacent its outer end and beyond the outermost limit of movement of the piston or plunger 29.

The valve casing is also provided with alined discharge ports 39 and 10, the former leading from the bore 41 in which the valve core is mounted, to the atmosphere, and the latter leading from said bore to the cylinder at a point between the outermost limit of movement of the piston and the head 30. The valve core is provided with a second passageway 42 disposed at an angle to the passageway 37 and constituting a discharge passageway which is designed to register with the passageways 39 and 40 for establishing communication therebetween when the feed passageway 37 is out of registry. The valve core has attached thereto a trigger 43 adapted for limited movement and designed to effect movement of the valve core in one direction, by pulling the trigger toward the cylinder 30, which cylinder is also in the nature of a hand grip. The valve core 36 and trigger are normally moved and held in the opposite direction under tension, by a spring 44, which is suitably connected at one end to a closure disk t5 keyed to the valve core and attached at its opposite end to the valve casing.

In use and operation, the gun body is constantly maintained filled with grease or other lubricant through the conduit 14, which is maintained under a pressure in excess of atmospheric pressure and which, for the purpose of illustration, will be assumed to be twenty pounds. The check valve 21 is maintained seated undera tension slightly in excess of twenty pounds so that when the valve 36 is in the osition illustrated in Fig. 1, the lubricant will be prevented from (lischarging through the nozzle from the body. It is obvious that the grease or lubricant will fill the nozzle up to the check valve 21, gaining access thereto through the port 17 and passage 16 in the plunger valve 15.

When the lubricant is to be discharged, the operator grasping the cylinder 30 in the manner of the hand grip of a pistol and pulling the trigger l3 rcarwardly against the action of the spring 4-1 turns the valve core 36 to the position illustrated in Fig. 2, where the passageway 37 establishes communication between the air supply pipe 33 and the pipe section 38. This causes compressed air of a pressure in excess of the normal ressure of the lubricant in the body, whic by way of example, will be assumed to he one hundred pounds, to enter the cylinder 30 between the outer end of the piston or plunger 29 and the head 31. The piston or plunger will move inwardly thereby simultaneously increasing the internal pressure of the lubricant contained in the body and swinging the rock lever 23 upwardly so that its forward end 26 will move the plunger valve 15 outwardly. The initial outward movement of the plunger valve will close the port 17 and will force the lubricant trapped within the nozzle between the plunger valve and the check valve past 1 the check valve and into the receivin device to which the nipple has previously sea attached. When the pull on the trigger 43 is released, the spring 44 will return the trigger and valve core 36 to the normal position illustrated in Fig. 1 so that the passageway 37 will be disposed out of registry with the air supply pipe 33 and pipe section 38 to cut off the air supply to the cylinder. At the same time, the passageway 42 will again establish communication between the discharge ports 39 and 40, permitting the exhaust of the compressed air within the cylinder so that the springs 18 and 28 will respectively move the valve plunger 15 and the rock lever 23 to their normal positions, thus bringing the port 17 of the plunger valve into communication with the body 10 for receiving a further charge of lubricant.

From the foregoing it will be seen that a comparatively simple and inexpensive yet highly etlicient grease gun has been set forth for economically feedin a lubricant to the parts to be lubricated, which is so constructed as to render the same convenient to handle and manipulate.

What is claimed is:

1. A grease gun, including a hollow body adapted to receive a constant supply of grease under pressure, a nozzle at one end earner of theloody having an inwardly forced normally open plunger valve and an outwardly opening normally closed check valve tensioned in excess of the normal lubricant pressure, and manually operated means for moving the plunger .valve outwardly to respectively close the same and force therefrom the quantity of grease trapped in the nozzle, through said check valve, said means consisting of a rock lever engaging the inner end of the plunger valve, a plunger cylinder open at one end of the gun body and having a closed outer end, a plungerin the cylinder, and means For introducing a fluid pressure in excess of the normal lubricant pressure to the cylinder between the closed end and the outer end of the plunger for effecting the inward movement of the plunger and rocking of the rock lever.

22. A grease gun, comprising a hollow body having an outlet nozzle, a plunger valve in the nozzle having a grease passage, means for normally moving the plunger valve inwardly to a position for establishing communication between the interior of the body and the nozzle, a'normally closed inwardly closing and outwardly opening check valve, a

discharge of the grease from the grease feed conduit leading a and communicating with the interior of the un body,

a plunger cylinder open to the be y at one end and closed at its opposite end, a plunger.

in the plunger cylinder, a compressed air supply conduit communicating with the spectively cut oil the compressed air supply to the plunger cylinder and to open the exhaust passage to the atmosphere,and serving when manipulated to close the exhaust pas sage and open the compressed air supply to a the plunger cylinder, a rock lever stulcrumed in the body having one end engaging the plunger valve and the opposite end disposed in the path of initial movement of the plungvalve is etlected to cut ofi communication between the nozzle and body and to efiect a through the check valve. NELSON STGRY, H1.

er, whereby when the plunger moves in-v. wardly, out-ward movement or the plunger nozzle 

